This invention relates to a synthetic soil composition for use in testing cleaning implements with or without separate or combined cleaning compositions, and a method of conducting such testing. Dusting devices and cleaning cloths need to pick up dust and dirt commonly found around the home. There is a need to be able to consistently test these cloths and cleaning devices to allow comparisons that will accurately correlate to how these cloths and devices will perform in the “real world”. Since there can be a wide variation of dust and dirt found in a typical home environment, and even the same home over differing periods of time, it is not considered feasible to collect soil, from an individual home, or even a series of homes, and use this as a reproducible testing material.
In the past, various artificial soils and test methods have been attempted for this purpose, but none have been found to correlate to what could be considered a typical home environment. For example, U.S. Pat. No. 5,928,948, of Malchesky, teaches a method for assessment and evaluation of a cleaning process comprising the steps of contaminating a porous material with a known soil, subjecting the porous material and the soil to the cleaning process to be assessed and evaluated, and evaluating the cleaning process on the basis of the soil not removed by the cleaning process. The test procedure of the present invention does not involve contamination of a porous material, and the soil employed by the patentee does not correspond to the soil of the present invention, but is more closely related to organic contamination more likely found in a medical, dental, surgical, or veterinary facility than in a typical home environment.
In U.S. Pat. No. 4,867,614, Freed teaches a composite mixture comprising soil and from about 0.1 to 5 percent of additive discrete fiber materials. The soil comprises natural soil selected from a group including sand, clay, and mixtures thereof, and the fiber materials are discrete fibers selected from man-made fiber forming substances and fiberglass, present to improve the punching resistance, total angle of internal friction, average total cohesion, and average initial tangent modulus of the soil. The present test soil is not reinforced so as to provide improved engineering properties as is that of the patentee. The composite soil mixture of the patent is provided to have improved load bearing capability and related engineering properties to benefit foundations and column supports, while the present invention is designed to correspond to a typical form of dirt or soil to be found in a typical home setting and the two soils have little in common.
U.S. Pat. Nos. 6,302,936 and 6,419,722, of Adam, claims an artificial soil composition comprising a homogenous mixture of a blending base, cellulose, bio-solids, calcium in any form burned crop waste or vegetation, and ammonium sulfate. Also claimed is a process for making the artificial soil. The purpose of the artificial soil proposed by Adam is for crop growth, rather than for a test material for evaluation of a cleaning composition or method, and the artificial soil of Adam comprises a very different mixture than that of the present invention.
In U.S. Pat. No. 5,312,661, Suzuki et al. teaches an artificial soil comprising porous granules consisting essentially of a plurality of thermoplastic resin foamed particles. The present invention does not include the presence of thermoplastic resin foamed particles, which are present in the patented composition to provide improved air permeability and drainage, which properties would not be of value in the purpose of the present invention.
A synthetic test soil is taught by Pfeifer, in U.S. Pat. No. 6,107,097, relating to test stains comprising isolated fibrin and/or fibrin precursors and blood plasma proteins. The present invention does not comprise fibrins or fibrin precursors, and does not relate to the testing of cleaning procedures for medical or surgical instruments.
In addition to the above, the following patents further show the state of the art: U.S. Pat. No. 5,137,460, of Middleton; U.S. Pat. No. 5,397,392, of Derr; U.S. Pat. No. 5,502,998, of Miller et al.; U.S. Pat. No. 5,583,165, of Kviesitis; Franklin et al. U.S. Pat. No. 4,792,363; Requejo et al., U.S. Pat. No. 5,090,975; Ahlberg et al., U.S. Pat. No. 5,461,749; Ditze et al., U.S. Pat. No. 5,877,138; Willman et al., U.S. Patent Application Publication No. US 2002/0050016; Lemay, U.S. Pat. No. 6,846,858; and Japanese Patent 7-35680, of Noritake et al. However, none of the prior art shows a soil which is typical of the type of soil or dirt to be found in a normal home or non-medical work environment, or a method for testing a cleaning composition, implement, or procedure suitable for use in such a normal home environment. It is also to be noted that the present invention is intended to be used in a hard surface cleaning environment, as opposed to a carpeted environment. Thus, the test soil of the present invention is intended to correlate to a soil or dust normally found on hard surface areas of the home, not in a carpeted area, and accordingly, the artificial test soil of the invention is not anticipated to be similar to soil removed from carpeting by vacuum cleaning.
Furthermore, these prior soil compositions relate generally to compositions which are normally found on a floor surface of a home, such as a carpeted, hardwood, tile, or other flooring surface. Thus, these test soils do not accurately reflect the types of fibers and particulates which form dust compositions that, in addition to being found on flooring surfaces, are also located on other surfaces elevated above the flooring surface, such as on tables, chairs, and window sills, among others. The reason for this is that the dust composition is formed of lighter components than typical soil compositions that enable the dust compositions to be carried in vertical as well as horizontal directions by air currents in the home. Thus, because of this difference in composition from normal household soils, it is desirable to develop an artificial or simulated dust composition that can be utilized to test various cleaning devices on their ability to pick up and remove household dust compositions, which are necessarily significantly different from soil compositions found virtually exclusively on flooring surfaces.